The White House Easter Egg Roll, with its poofy, pastel dresses, cute little-boy suits and squealing children chasing eggs, will take a turn for the political this year.

Hundreds of gay and lesbian parents, some from across the country, are planning to line up overnight tomorrow to get tickets to the 128-year-old Washington ritual Monday, to blanket the White House lawn with a realistic mosaic of their families.

"I don't think this is a protest. Showing up, participating fully in an American tradition, showing Americans that we do exist, that in our minds isn't a protest," said Jennifer Chrisler, executive director of the Family Pride Coalition, an advocacy group for gay, lesbian, bisexual and transgender parents based in Washington.

Critics have denounced the parents for politicizing such an iconic, American event.

"I think it's inappropriate to use a children's event to make a political statement," said Mark D. Tooley, who directs the United Methodist committee at the Institute on Religion and Democracy. He wrote a column earlier this year in the Weekly Standard saying gay civil rights groups were making "covert plans to crash the annual White House Easter egg roll."

Other critics have dubbed this year's Easter mobilization "Brokeback Bunny" in online message boards, a reference to "Brokeback Mountain," the Oscar-winning movie about two gay men.

The springtime rite also has been targeted by the Humane Society of the United States, which asked the White House to put the chicken before the egg and use only eggs laid by uncaged hens. The White House nixed the cage-free idea pretty quickly, saying that free-range hens are few and far between and that officials want to get their 14,200 eggs from caged chickens because of food safety concerns.

There has been some hand-wringing at the White House over the planned gay and lesbian mobilization. White House spokesman Scott McClellan has been fielding questions about it since January.

The National Park Service finally laid out the rules yesterday. The Easter tradition is open to the public, and tickets are given to people on a first-come, first-served basis. The event is open to all children, but at least one child in the group must be 7 or younger, and there can be no more than two adults in the group.

First lady Laura Bush's office yesterday reiterated, "Mrs. Bush wants to make sure all families are welcome to attend the Easter egg roll."

The egg roll has been a tradition since 1878, with its petting zoos, staff members hopping about in bunny costumes and maypole dancing. The president sometimes makes a brief appearance, and the first lady often reads a story. The White House was silent about their plans for this year.

Usually, the only thing that separates the egg rollers from others is their willingness to sit on a cold sidewalk for hours, in the dark, waiting to pick up tickets. In the past, people have set up camp outside the White House as early as 4 a.m.

To ensure their place on the lawn, gay and lesbian parents are queuing up about 8 p.m. tomorrow. They aren't going to carry signs or chant slogans.

"The message is that gay and lesbian families are everywhere in this country," said Chrisler, whose group is one of about a dozen planning the event. "We care about the same things that all parents care about: providing our children with every opportunity and every experience possible."

The parents considered wearing some of kind T-shirt that would identify them as a group. But because all those T-shirts could look like a protest -- and Washington weather isn't always T-shirt-friendly in April -- the group settled on rainbow-colored leis as a unifying symbol, said Colleen Gillespie, a professor at New York University who began the movement after visiting last year's egg event with her partner and their daughter, Ella.

"It is ironic. If we didn't identify ourselves somehow, once again, we're invisible, and our presence there, it loses its power," Gillespie said.

The idea came to her after standing in the ticket line for hours last year. She began to talk to people in line. They weren't her Brooklyn friends or her university colleagues. They were different.

"I met a family that was home-schooling eight kids, a guy reading a Bible on the Palm Pilot. And they all met me, a lesbian parent," Gillespie said. "Sure, there was a little hesitation, little awkwardness. But now, when someone is on TV saying negative things about my family, they have a visual picture of what that family looks like. It's just me, a mom. And I'm waiting in the freezing cold so my daughter could get some Easter eggs."